Si Tritone Substitution

Si Tritone Substitution — ii – bII7 – I

In the B tritone substitution (C#m – C – B), the dominant V7 is replaced by a chord a tritone away — sharing the same guide tones but approaching the I from a half-step above. Lydian Dominant fits the substitute chord perfectly, while Dorian covers the ii. Bebop Major outlines the resolution. With seventh voicings (C#m7 – C7 – BMaj7), the chromatic voice-leading creates the sophisticated sound central to bebop harmony.

Playing in Si major

B major mixes barre and open elements. The B chord itself is a barre at fret 2, but E and A are comfortable open chords forming the IV and V. The open B string rings as the root, allowing creative drone-based arrangements. B is a intermediate-level key on guitar because the open B string rings as the root and the open E strings provide the 4th — useful for sus4 voicings and drone effects. This key mixes open and barre shapes, making it a good intermediate challenge that builds fretboard fluency.

Voice Leading

The bass line moves through C# to C (descending half step), C to B (descending half step). A half-step bass movement creates a strong leading-tone pull that demands resolution. The predominantly stepwise bass motion creates smooth, connected voice leading. When the progression loops, the bass returns from B to C# by whole step.

Capo Transposition

To play in B using familiar open chords: capo 2 with open A shapes; capo 4 with open G shapes; capo 7 with open E shapes. Choose the capo position that gives you the voicings you prefer — lower capo positions produce a fuller sound, while higher positions create a brighter, mandolin-like timbre.

Scales for Soloing

B major pentatonic works because every note is either a chord tone or a safe passing tone — there are no avoid notes. For soloing, this means you can play freely without clashing. Over dominant seventh chords, B Mixolydian adds the flat seventh for an authentic blues-rock edge.

Strumming Pattern

Use Freddie Green-style comping: short, muted chord stabs on beats 2 and 4 at 120-160 BPM. Keep the chords tight and percussive, lifting your fretting hand slightly after each attack to control sustain.